As a method for manufacturing a laminated iron core, for example, a method for laminating iron core pieces with a thickness of 0.3 mm or less and bonding the iron core pieces by caulking etc. is widely implemented. However, the bonding by the caulking has a problem that the iron core pieces conduct in a lamination direction and eddy current loss is caused and motor performance is decreased. Also, in the case of the caulking bonding, the adjacent iron core pieces are pressed in and fitted by the caulking, with the result that shape accuracy is influenced, for example, a warp occurs on a surface of the laminated iron core, or straightness is decreased.
In order to solve the problems described above, a manufacturing method described in Patent Literature 1 is proposed. FIGS. 17(A) and 17(B) are diagrams showing the manufacturing method described in Patent Literature 1. As shown in FIGS. 17(A) and 17(B), the method for injecting a resin 82 into a bond hole 81 formed by communicating a through hole bored in iron core pieces 80 in a lamination direction and curing the resin 82 to thereby bond the iron core pieces 80 in a laminated state to manufacture a laminated iron core 83 is proposed. Since the resin 82 is an insulator, the adjacent iron core pieces 80 do not conduct and further, a decrease in shape accuracy due to an influence of caulking is eliminated.
However, Patent Literature 1 does not describe a step of blank and laminating the iron core pieces 80 to a step of injecting the resin 82, a conveyance method and a conveyance form. The ejected iron core pieces 80 can be conveyed one by one, but there is a problem that conveyance becomes complicated and trouble with handling in the next step is taken and workability is bad. Also, when the iron core pieces are conveyed one by one, the iron core piece is directly gripped by conveyance means and the iron core piece with a thin thickness may be deformed, and there is a problem of influencing quality of a product.
In order to solve the problems described above, a manufacturing method described in Patent Literature 2 is proposed. FIGS. 18(A) and 18(B) are diagrams showing the manufacturing method described in Patent Literature 2. As shown in FIGS. 18(A) and 18(B), a composite iron core piece 95 including iron core pieces 91 and dummy piece parts 93 joined to the iron core pieces 91 through joining piece parts 92 is blanked and formed, and this composite iron core piece 95 is caulked and laminated through caulking 93a formed in the dummy piece parts 93, and a composite laminated iron core 99 having a laminated iron core 96 used as a product, joining parts 97 and dummy laminated parts 98 is formed. Then, it is contemplated to apply the method for bonding the laminated iron core 96 by a weld part 100 formed on a side surface and cutting the dummy laminated parts 98 at the joining parts 97 and manufacturing the laminated iron core 96.